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1110 documents found for International Journal
Piezoelectric materials parameters for piezoelectric thin films in GHz applications
P. Muralt, J. Conde, A. Artieda, F. Martin, M. Cantoni
Published online : 01-02-2009
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Piezoelectric thin films have existing and promising new applications in microwave filter technologies. The final performance depends on many parameters, and very specifically on the materials properties of each involved material. In this article, materials and properties for thin-film bulk acoustic wave resonators are discussed on some selected issues: the piezoelectric coefficients and acoustic
Vertical displacement detection of an aluminum nitride piezoelectric thin film using capacitance measurements
Mahmoud Al Ahmad, Robert Plana
Published online : 01-02-2009
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Piezoelectric materials have a strong interaction between their mechanical and electrical properties that translates into innovative components and circuits architectures. This work describes an original method using the electromechanical properties of the aluminum nitride (AlN) piezoelectric material to characterize its vertical extension when an electric field is applied. The novel techniques ba
High-frequency monolithic thin-film piezoelectric-on-substrate filters
Reza Abdolvand, Farrokh Ayazi
Published online : 01-02-2009
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A class of micromachined acoustic filters is presented in which the number of individual resonant structures is reduced to 1 (monolithic filter). This resonant structure is comprised of a stack of thin-film piezoelectric-on-silicon. Symmetric and anti-symmetric resonance modes (dual modes) of the silicon structure are piezoelectrically excited and coupled to realize a 2-pole narrowband filter. Hig
Lithographical bending control method for a piezoelectric actuator
Tamio Ikehashi, Etsuji Ogawa, Hiroaki Yamazaki, Tatsuya Ohguro
Published online : 01-02-2009
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This paper presents the theoretical formulation of a lithographical bending control (LBC) method that uses lithographical degrees of freedom to control the bending of a multilayered beam. LBC is applied to a piezoelectric actuator that uses PZT as the piezoelectric material. The theoretical model is compared with measurements using a weakly fixed bridge structure suited for curvature measurement.
Experimental system level analysis of a concurrent dual-band power amplifier for WiMAX and WCDMA applications
Alessandro Cidronali, Iacopo Magrini, Niccol Giovannelli, Massimiliano Mercanti, Gianfranco Manes
Published online : 01-04-2009
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This paper presents a feasibility study for the implementation of a concurrent dual-band power amplifier (PA) design suitable for 1.98GHz WCDMA and 3.42GHz WiMAX digital systems. The proposed PA design was compared with a test bed based on a pair of dedicated single-frequency band PAs. The dual-band PA exhibited simultaneous peak output power levels of 24 and 17dBm in the lower and in the highe
Concurrent dual-band SiGe HBT power amplifier for Wireless applications
Vittorio Camarchia, Rocco Giofr, Iacopo Magrini, Luca Piazzon, Alessandro Cidronali, Paolo Colantonio, Simona Donati Guerrieri, Giovanni Ghione, Franco Giannini, Marco Pirola, Gianfranco Manes
Published online : 01-04-2009
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This paper presents an investigation of a concurrent low-cost dual-band power amplifier (PA) fabricated in SiGe technology, able to simultaneously operate at two frequencies of 2.45 and 3.5-GHz, including an evaluation of its system level performance potentiality. Taking into account the technology novelty and the lack of device characterization and modeling, a hybrid (MIC) approach has been adopt
Behavioral modeling and linearization of a millimeter-wave power amplifier
Ilan Melczarsky, Pere L. Gilabert, Valeria Di Giacomo, Eduard Bertran, Fabio Filicori
Published online : 01-04-2009
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The use of digital predistortion for linearizing a millimeter-wave power amplifier (PA) is investigated. A PA operating at 38GHz is designed using an accurate non-quasi-static transistor model, taking into account both short- and long-term memory effects. A realistic test signal is then used for the identification of a nonlinear auto-regressive moving average (NARMA) behavioral model of the PA. T
Nonlinear modeling of InP devices for W-band applications
Davide Resca, Valeria Di Giacomo, Antonio Raffo, Rafael Cignani, Alberto Santarelli, Giorgio Vannini, Fabio Filicori, Dominique Schreurs, Farid Medjdoub, Nicolas Thouvenin, Christophe Gaquire
Published online : 01-04-2009
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A recently proposed technique for the distributed modeling of extrinsic parasitic effects in electron devices is used for the very first time in conjunction with a lumped equivalent circuit model for the intrinsic device.
Nonideality sources and implementation considerations in polar transmitters
Jos A. Garca, Jos C. Pedro, Pedro Miguel Cabral, Christian Fager, Hossein Mashad Nemati, Anding Zhu, Paolo Colantonio
Published online : 01-04-2009
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In this paper, the main nonidealities appearing in polar transmitters will be addressed, together with several implementation considerations. Special attention will be paid to the role of AM modulation nonlinearity and parasitic AM-to-PM conversion, once architecture mechanisms such as time-delay mismatch between branches or limited bandwidth in the amplitude path are controlled. The device limiti
A semi-lumped microstrip UWB bandpass filter
Darine Kaddour, Jean-Daniel Arnould, Philippe Ferrari
Published online : 01-02-2009
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In this paper, a miniaturized bandpass filter for ultra-wide-band applications is proposed. It is based on the embedding of high-pass structures in a low-pass filter. A semi-lumped technology combining surface-mounted capacitors and transmission lines has been used. The filter design rules have been carried out. Furthermore, two filters having a 3-dB fractional bandwidth of 142 and 150%, centered
Mitigation of wideband interference on UWB-IR transmission using multi-carrier templates
Madan Kumar Lakshmanan, Homayoun Nikookar
Published online : 01-02-2009
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Ultra wideband (UWB) wireless systems are highly susceptible to interference from other services. To reduce the effect of interference from co-existing sources such as the WLAN standard IEEE 802.11a on UWB Communication, the construction of a modified template waveform using multi-carrier sinusoids is proposed in Ohno and Ikegami (2003), Ohno et al. (2004), Ohno and Ikegami (2006), and Lakshmanan
Criteria for the evaluation of linear two-port stability using two geometrically derived parameters
Chinchun Meng, Hung-Ju Wei, Po-Hsing Sun
Published online : 01-02-2009
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Two geometrically derived stability parameters, ? (or ) and ??(or ?), are used to analyze the stability of a two-port network. The magnitudes of both ? (or ) and ?? (or ?) parameters determine geometrical relations between the stability circle and the unit Smith chart in the (or ) plane. |?| (or ||) is defined as the minimum distance from the stability circle to the origin of the unit Smith
A correlation of capacitive RF-MEMS reliability to AlN dielectric film spontaneous polarization
Eleni Papandreou, George Papaioannou, Tomas Lisec
Published online : 01-02-2009
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This paper investigates the effect of spontaneous polarization of magnetron-sputtered aluminum nitride on the electrical properties and reliability of Radio Frequency ? Micro-Electro-Mechanical Systems capacitive switches. The assessment is performed with the aid of application of thermally stimulated polarization currents in metal-insulator-metal capacitors and temperature dependence of device ca
Improved IP2 calibration method using a perturbance-based algorithm
Karim Aoulad Ali, Philippe Barr, Guillaume Andrieux, Jean-Franois Diouris
Published online : 01-02-2009
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To achieve a high IIP2 level on a mixer, static calibration techniques have been developed. Most of them are based on an intentional introduction of a calibrated mismatch in the structure of the mixer. They are performed at production stage. It is also possible to automate them but their activation is strongly limited in portable devices because of system restrictions. Furthermore, IIP2 is sensiti
GaN devices for power amplifier design
Teresa M. Martn-Guerrero, Damien Ducatteau, Carlos Camacho-Pealosa, Christophe Gaquire
Published online : 01-04-2009
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This paper describes some aspects of the fabrication and modeling of a GaN device to be employed in a power amplifier covering one WiMAX frequency band. The work has been carried out in the frame of the TARGET's NoE work package WiSELPAS. Details concerning the AlGaN/GaN device technology and the performed linear and nonlinear measurements are provided. Since these new devices require specific non
Piezo-controlled microwave devices
Yuriy M. Poplavko, Vitally I. Molchanov, Yuriy I. Yakimenko
Published online : 01-02-2009
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At present, millimeter wave fast tunable components are required for telecommunication systems, car collision prevention radar, etc. The only mechanical way of control inserts practically no loss in the frequency agile system. That is why micro-electromechanical systems devices are being studied intensively. In an overview, an alternative way ? piezo-electromechanical tuning of microwave component
Coherent sources separation based on sparsity: an application to SSR signals
Nicolas Petrochilos, Gaspare Galati, Emilio Piracci
Published online : 01-06-2009
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Systems based on secondary surveillance radar (SSR) downlink signals, both with directional and with omni-directional antennae (such as in multilateration), are operational today and more and more installations are being planned. In this frame, high-density traffic leads to the reception of a mixture of several overlapping SSR replies. By nature, SSR sources are sparse, with amplitude equal to ze
Airborne passive location based on combined time and frequency difference of arrival
Gaetano Severino, Antonio Zaccaron, Riccardo Ardoino
Published online : 01-06-2009
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Passive location techniques have always been considered an important topic and recently, thanks to digital signal processing (DSP) advances, new methods are being studied and experimented with. The possibility to passively locate radar emitters avoiding transmission is crucial in a variety of military applications, in particular when a flying platform (aircraft or helicopter) is entering an unknow
1090MHz channel capacity improvement in the air traffic control context
Emilio G. Piracci, Gaspare Galati, Nicolas Petrochilos, Fabrizio Fiori
Published online : 01-06-2009
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The aim of this study is to increase the capacity of the 1090MHz secondary surveillance radar (SSR) channel by novel transmission and decoding techniques. In particular, multilateration stations have omni-directional antennae; hence considering aircraft traffic and including the extension of surveillance to cooperating vehicles, the reception of superimposed signals is more and more probable. We
Potential accuracy of object localization with multilateration systems
Victor Chernyak
Published online : 01-06-2009
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Multilateration (MLAT) systems and wide area MLAT (WAM) systems are particular cases of multisite (multistatic) radar systems (MSRSs): passive MSRSs (PMSRSs) with known expected signal waveforms. One of the most stringent requirements on an MLAT system is a very high accuracy of target (emitter) localization. In view of this, the potential accuracy of emitter localization (PAEL) based on Cramer?Ra
Subspace-based estimation of time of arrival and Doppler shift for a signal of known waveform
V.V. Latyshev
Published online : 01-06-2009
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The subspace-based technique is used for the estimation of the time of arrival and Doppler shift of a signal of known waveform. The tool to find required subspaces is a special orthogonal decomposition of received data. It allows one to concentrate Fisher information on the desired parameter in just a few of the first terms of the decomposition. This approach offers a low-dimensional vector of suf
Novel concepts for surface movement radar design
Konstantin Lukin, Anatoliy Mogila, Pavlo Vyplavin, Gaspare Galati, Gabriele Pavan
Published online : 01-06-2009
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Traditional millimeter-wave surface movement radar (SMR) has been designed and tested. A novel concept for the design of a new SMR is suggested based on synthetic aperture antenna and noise radar technology. It enables designing SMR without mechanical rotation of an antenna, but applying several nonmoving synthetic aperture antennas instead. Application of noise radar technology is also considered
ISAR imaging of helicopters using millimeter wave radars
Helmut Essen, Manfred Hgelen, Alfred Wahlen, Karsten Schulz, Klaus Jger, Marcus Hebel
Published online : 01-06-2009
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The capabilities of millimeter wave radars have been demonstrated for a long period of time for missile seeker applications and for automotive radars. The technological advantages of this type of radar can be adapted to security applications in air traffic management at short and medium range as well as on the ground. The application discussed in this paper focuses on inverse synthetic aperture ra
Two efficient localization algorithms for multilateration
Mauro Leonardi, Adolf Mathias, Gaspare Galati
Published online : 01-06-2009
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Two localization algorithms for multilateration systems are derived and analyzed. Instead of the classical time difference of arrival (TDOA), a direct use of the time of arrival (TOA) is made. The algorithms work for arbitrary spatial dimensions and overdetermined systems. These derivations are tested in a real-case implementation with simulated data (in particular, the multilateration (MLAT) syst
Evaluation of some features for extended target extraction in polarimetric and non-polarimetric radar
Piet van Genderen, Vsevolod Kovalenko
Published online : 01-06-2009
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Detection in most surveillance radars is based on the condition of point targets against a more or less homogeneous background. Currently, the resolution of many new types of radar is increasing, at least in the range dimension. Therefore many objects can no longer be considered as points. Also as a consequence, the background is becoming more diverse, in statistical terms. The scene addressed in
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